The literature is replete with descriptions of surgical devices. For example, U.S. Pat. No. 4,705,038 to Sjostrom et al. describes a surgical system for powered instruments. The system includes a handpiece containing a motor and including a recess adapted to receive one of a plurality of surgical devices. A pair of reed switches is disposed within the recess, and each of the surgical devices includes one or two magnets adapted to actuate the reed switches in a particular combination when the device is assembled with the handpiece. The combination of reed switches activated by the magnets of the assembled handpiece and surgical device identifies to the system the surgical device so assembled with the handpiece. The number of possible surgical devices identifiable by this system is limited to the four possible combination of up to two magnets.
U.S. Pat. No. 4,995,877 to Ams et al. describes a device with a rotationally-driven surgical instrument. The device includes a hand-held element containing a driving motor for driving a tool insert. The device further includes a control unit having a storage unit for storing operational data manually set by the user of the device. Such data may be transferred to a code carrier, which is insertable into a plug-in facility.
U.S. Pat. No. 5,249,583 to Mallaby describes an electronic biopsy instrument with wiperless position sensors. A slotted disc and a cam are affixed to a drive shaft, which is driven by a motor. A pair of sensors is arranged so that each sensor is activated when the slot of the slotted disc is positioned over the sensor to thereby determine the position of a cannula and a stylet of the instrument. The sensors, slotted disc, cam, motor and rechargeable batteries for powering the instrument are contained within a housing of the instrument.
U.S. Pat. No. 5,383,880 to Hooven describes an endoscopic surgical system with sensing means. The instrument includes a motor disposed within a hand-held housing. A sensor is provided in the head of an instrument of the system for sensing the blood oxygen content of adjacent tissue.
Similarly, U.S. Pat. No. 5,395,033 to Byrne et al. describes an endoscopic surgical instrument having a pair of jaws. A permanent magnet is disposed in a distal end of one of the jaws, and a magneto-resistive sensor is disposed in a distal end of the other one of the jaws. The magnet produces a magnetic field between the jaws, and the sensor measures the variations in the magnetic field so that the distance between the jaws may be determined.
U.S. Pat. No. 5,467,911 to Tsuruta et al. describes a surgical device for stapling and fastening body tissues. The device includes an operation section and an insertion section, which is detachably attachable to the operation section.
U.S. Pat. Nos. 5,518,163, 5,518,164 and 5,667,517, all to Hooven, describe an endoscopic surgical system, which includes a motor disposed in a handle portion. A sensing member, which is used to sense the blood oxygen content of adjacent tissue, is disposed in a head of the instrument. A contact is also provided in the head of the instrument. When a firing nut of the system has moved forward in the head to drive and form surgical staples disposed therein, the firing nut engages the contact, thereby reversing the motor to retract the firing nut.
U.S. Pat. No. 5,653,374 to Young et al., U.S. Pat. No. 5,779,130 to Alesi et al. and U.S. Pat. No. 5,954,259 to Viola et al. describe a self-contained powered surgical apparatus, which includes a motor assembly and power source disposed within a hand-held instrument body.
These instruments and systems described above suffer numerous disadvantages. For example, in several of the above-described instruments and systems, a motor is disposed within a handle of the instrument. Due to size considerations, these motors generally provide limited torque. In certain of the instruments and systems described above, a battery is provided within the handle for powering the motor. Such battery systems, however, provide limited electrical power to the motors, further limiting the torque output by the motors.
In addition, it is generally not possible to accurately ascertain the positions of the operative elements of the aforementioned instruments and systems.
A further disadvantage of the above-described instruments and systems is that such instruments and systems typically require manual manipulation and operation. When a motor is provided in the handle of such instruments, manual manipulation and operation is awkward and cumbersome to the operator.